(i) Field of the Invention
The present invention relates to an apparatus for measuring calories consumed during sleep.
(ii) Description of the Related Art
Heretofore, in a technology disclosed as an apparatus that controls a sleep environment including sleep environment temperature based on the body condition of a user of the apparatus (hereinafter simply referred to as “user”), a technique of calculating calories consumed during sleep from the bioelectrical impedance value, body weight value and information about body oscillations during sleep of the user has been disclosed (for example, refer to Patent Publication 1).
Further, in the same technology as described above, a technique of calculating consumed calories from the skin temperature and sleep stage during sleep of a user has been disclosed (for example, refer to Patent Publication 2).    Patent Publication 1
Japanese Patent Laid-Open Publication No. 2003-164496    Patent Publication 2
Japanese Patent Publication No. 7-114142
However, in the technique described in Patent Publication 1 which estimates information about body oscillations during sleep from a respiration rate and a heart rate, since the intensities (magnitudes) of respiration and heartbeats are not constant, e.g. consumed calories calculated based on deep breathing and consumed calories calculated based on shallow breathing cannot be said to be the same consumed calories even when the number of breaths is the same, it is difficult in some cases to calculate accurate consumed calories only from body oscillation information based on the respiration rate and the heart rate.
Further, in the technique described in Patent Publication 2 which uses a correlation between consumed calories and sleep stages, since it does not take into consideration differences in consumed calories at each sleep stage among individuals, it cannot be said that accurate consumed calories are calculated by the technique.
Therefore, the present invention solves the above problems and provides an apparatus for measuring calories consumed during sleep. The apparatus measures more accurate consumed calories during sleep by determining the magnitudes of body oscillations during sleep and determining calories consumed during sleep from consumed calories based on both body oscillations caused by breathing during sleep and body oscillations caused by heartbeats during sleep (hereinafter referred to as “breathing/heartbeat oscillations”) and consumed calories based on the intensities of body oscillations (hereinafter referred to as “body motions”) other than the above breathing/heartbeat oscillations during sleep.